/**
 * Copyright (C) <2021>  <chen junwen>
 * <p>
 * This program is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * <p>
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License along with this program.  If
 * not, see <http://www.gnu.org/licenses/>.
 */
package io.mycat.calcite.sqlfunction.datefunction;

import org.apache.calcite.avatica.util.DateTimeUtils;
import org.apache.calcite.linq4j.function.Parameter;
import org.apache.calcite.schema.ScalarFunction;
import org.apache.calcite.schema.impl.ScalarFunctionImpl;

import java.io.Serializable;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Date;

public class FromUnixTimeFunction extends MycatDateFunction {
    public static ScalarFunction scalarFunction = ScalarFunctionImpl.create(FromUnixTimeFunction.class,
            "fromUnixTime");
    public static FromUnixTimeFunction INSTANCE = new FromUnixTimeFunction();

    public FromUnixTimeFunction() {
        super("FROM_UNIXTIME", scalarFunction);
    }

    public static LocalDateTime fromUnixTime(long unix_timestamp) {
        Date date = new Date(unix_timestamp * 1000);
        LocalDateTime localDateTime = LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
        return localDateTime;
    }
}

